Electronic and semiconductor components are used in ever-increasing numbers of consumer and commercial electronic products, communications products and data-exchange products. Examples of some of these consumer and commercial products are televisions, computers, cell phones, pagers, palm-type or handheld organizers, portable radios, car stereos, or remote controls. To meet the requirements for faster performance, the characteristic dimensions of features of integrated circuit devices have continued to be decreased. Manufacturing of devices with smaller feature sizes introduces new challenges in many of the processes conventionally used in semiconductor fabrication.
As a result of the size decrease in these products, the components that comprise the products must also become smaller and/or thinner. Examples of some of those components that need to be reduced in size or scaled down are microelectronic chip interconnections, semiconductor chip components, resistors, capacitors, printed circuit or wiring boards, wiring, keyboards, touch pads, and chip packaging.
When electronic and semiconductor components are reduced in size or scaled down, any defects that are present in the larger components are going to be exaggerated in the scaled down components. Thus, the defects that are present or could be present in the larger component should be identified and corrected, if possible, before the component is scaled down for the smaller electronic products.
In order to identify and correct defects in electronic, semiconductor and communications components, the components, the materials used and the manufacturing processes for making those components should be broken down and analyzed. Electronic, semiconductor and communication/data-exchange components are composed, in some cases, of layers of materials, such as metals, metal alloys, ceramics, inorganic materials, polymers, or organometallic materials. The layers of materials are often thin (on the order of less than a few tens of angstroms in thickness). In order to improve on the quality of the layers of materials, the process of forming the layer—such as physical vapor deposition of a metal or other compound—should be evaluated and, if possible, modified and improved.
In order to improve the process of depositing a layer of material, the surface and/or material composition must be measured, quantified and defects or imperfections detected. In the case of the deposition of a layer or layers of material, it is not the actual layer or layers of material that should be monitored but the material and surface of that material that is being used to produce the layer of material on a substrate or other surface and the intervening apparatus, such as a coil or collimator, that are placed between the target material and the substrate or other surface that should be monitored. For example, when depositing a layer of metal onto a surface or substrate by sputtering a target comprising that metal, the atoms and molecules being deflected or liberated from the target must travel a path to the substrate or other surface that will allow for an even and uniform deposition. Atoms and molecules traveling natural and expected paths after deflection and/or liberation from the target will unevenly deposit on the surface or substrate, including trenches and holes in the surface or substrate, the surrounding shield and other exposed surfaces inside the chamber. For certain surfaces and substrates, it may be necessary to redirect the atoms and molecules leaving the target in order to achieve a more uniform deposition, coating and/or film on the surface or substrate.
To this end, it would be desirable to develop and utilize a deposition apparatus and sputtering chamber system that will maximize uniformity of the coating, film or deposition on a surface and/or substrate. Coils and coil sets, such as those that are being produced by Honeywell Electronic Materials™, are consumable products placed inside the sputtering chamber or ionized plasma apparatus that redirect sputtered atoms and/or molecules to form a more uniform film and/or layer on a substrate and/or suitable surface. For background purposes, the coil is present in these systems and/or deposition apparatus as an inductively coupling device to create a secondary plasma of sufficient density to ionize at least some of the metal atoms that are sputtered from the target. In an ionized metal plasma system, the primary plasma forms and is generally confined near the target by the magnetron, and subsequently gives rise to atoms, such as Ti atoms, being ejected from the target surface. The secondary plasma formed by the coil system produces Ti, Cu & Ta ions (depending on material being sputtered). These metal ions are then attracted to the wafer by the field in the sheath that forms at the substrate (wafer) surface. As used herein, the term “sheath” means a boundary layer that forms between a plasma and any solid surface. This field can be controlled by applying a bias voltage to the wafer and/or substrate.
Conventional coils are suspended on ceramic electrical insulators to prevent the coil potential from shorting to the processing chamber shields that are attached to the process chamber walls, and are thus, at ground potential. The metal plasma will coat the ceramic insulators and form a short circuit. Shields, formed in the shape of cups, are placed around the ceramic to provide an optically dense path from the plasma to the ceramic that would prevent the deposition of metals on the ceramics. Typically, a small cup-like shield that encompasses the ceramic is attached to the coil and a larger cup-like shield is attached to the smaller cup-like shield such that the cups are electrically isolated from each other but collectively work to shield the ceramic. Under heat stress, the coil expands and reduces the nominal gap between the backside of the coil and the edge of the outside cup-like shield, creating a short circuit and interrupting the deposition process on the substrate.
In addition to those problems and potential defects described above, particle generation during physical vapor deposition (PVD) is one of the most detrimental factors that reduce the yield of functional chips in microelectronic device fabrication. In PVD systems, particles are mainly generated when deposits build up on surrounding chamber components and stress induced cracking occurs, particularly on the coil that is being used in the ionized metal plasma (IMP) and self ionized plasma (SIP) sputtering systems. Deposition mainly occurs on top of these coils.
Conventional coils and coils sets can be expensive and difficult to manufacture because of the size of the metal or metal alloy rod being used. Therefore, it would be desirable to develop better shaped and sized coils that are ultimately more cost efficient coils and coil sets for utilization with a deposition apparatus, a sputtering chamber system and/or ionized plasma deposition system without causing shorts, interruptions to the deposition process or inappropriate metal deposition. It would also be desirable to ensure that those new coils and coil sets will have a similar lifetime relative to the target being used, because decreasing the difference in lifetime between the coils, coil sets and targets would, at the very least, decrease the number of times the apparatus or systems have to be shut down to replace coils before replacing both the coil and target.